/Engine/Source/Runtime/Analytics/Analytics/Public/AnalyticsEventAttribute.h
Hack to allow copy ctor using an rvalue-ref. This class only "sort of" acts like an immutable class because the const members prevents assignment, which was not intended when this code was changed.
FAnalyticsEventAttribute ( [FAnalyticsEventAttribute](API\Runtime\Analytics\FAnalyticsEventAttribute) && RHS )